Display panel having particle source

ABSTRACT

A gas-filled display panel includes a plurality of rows and columns of display cells and associated electrodes. The panel also includes a trigger means, known as a keep-alive cell, to facilitate the turn-on of the display cells. The keep-alive cell is heat-sensitive, and it is secured in the panel by techniques which operate at room temperature.

United States Patent [151 3,684,909

Caras 1 Aug. 15, 1972 [54] DISPLAY PANEL HAVING PARTICLE 2,847,615 8/1958 Engelbart ..3l5/84.6

SOURCE 2,925,530 2/ l 960 Engelbart ..3 l 5/ 84.6

[72] Inventor: Bernard Caras, Princeton, NJ.

Primary ExammerRoy Lake [73] Assignee: Burroughs Corporation, Detroit, Assistant Examiner-Palmer C. Demeo Mlch- Attorney-Kenneth L. Miller and Robert A. Green [22] Filed: Jan. 29, 1970 [57] ABSTRACT [21] Appl. No.: 6,828

A gas-filled display panel includes a plurality of rows and columns of display cells and associated electrodes. [52] US. Cl. ..313/54, 313/ 198, 313/220, The

panel also includes a trigger means, known as a [51] Int. Cl. H01] 17/16 Holj fills i i g keep-alive cell, to facilitate the turn-on of the display [58] Field 'g 313/220 221 109 5 cells. The keep-alive cell 1s heat-sensltive, and it is 3157169 secured in the panel by techniques which operate at room temperature. [561 References CM 17 Claims, 10 Drawing Figures UNITED STATES PATENTS 2,845,568 7/1958 West et al ..3l3/54 X 200 |6pB\ eocl lea om I30) 4'' l I 71 1 7 1 I [I], |/,v/ 1

I L 2O \20 4 lGOA PATENTEU ms 15 I972 SHEET 1 OF 4 INVENTOR.

Bernard C qrqg ATTORNEY BACKGROUND OF THE INVENTION The principles of the invention apply to all types of gas-filled display devices which are considered to require a glow triggering mechanism to achieve suitably high-speed firing or turn-on of the devices. According to one theory, the triggering mechanism provides electrons which are considered necessary to start the glow discharge process in a cell. In one arrangement for obtaining these initiating electrons, an auxiliary gas cell, called a keep-alive cell, is built into the panel and is held on continually by means of applied potential so that it is a constant source of electrons or other excited particles. This arrangement operates satisfactorily; however, more efficient keep-alive arrangements which do not require applied potentials are known, but one of these, which is particularly desirable, is adversely affected by processing steps used in making gas discharge devices.

SUMMARY OF THE INVENTION A display panel embodying the invention includes a glow triggering mechanism which is sensitive to elevated temperature but is secured to the panel after all high-temperature processing steps have been carried out and by a process which does not require high temperatures.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective exploded view of a display panel embodying the invention;

FIG. 2 is a sectional view along the lines 2-2 in FIG.

FIG. 3 is a sectional view along the lines 3-3 in FIG.

FIG. 4 is a sectional view of a modification of a portion of the device shown in FIG. 3;

FIG. 5 is a sectional view along the lines 5-5 in FIG.

FIG. 6 is a sectional view along the lines 6-6 in FIG.

FIG. 7 is a sectional view along the lines 7-7 in FIG.

FIG. 8 is a sectional view along the lines 88 in FIG. 1;

FIG. 9 is a schematic representation of some of the electrodes in the display panel of FIG. 1; and

FIG. 10 is a sectional view of a portion of the display panel of FIG. 1 at one stage in its manufacture.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The display panel described herein is a thin, flat, sheet-like member which may have substantially any desired size and shape from, for example, postage stamp size to wall size, and it may include substantially any number of display cells. The panel may also include any suitable ionizable gas such as neon, argon, xenon, etc., singly or in combination, with a vapor of a metal such as mercury usually included in the gas to minimize cathode sputtering.

A display panel 10 embodying the invention includes a bottom plate of an hermetic, dielectric material, such as glass or ceramic, which has a top surface 30, a

' bottom surface 40, an upper edge 50, a lower edge 60,

a left edge 70, and a right edge 80. The plate 20 has a plurality of parallel slots or channels 90 extending a convenient distance into the body of the plate from the top surface 30. For purposes of illustrating and describing the invention, the panel is orientated so that the slots 90 extend horizontally across plate 20 from the left edge to the right edge 80.

The array of slots is suitably positioned between the upper and lower edges of plate 20, with the first slot 90A being closest to the upper edge 50 of the plate, and the last slot 90E being closest to the lower edge 60 of the plate.

The slots 90 are all identical in size, shape, width, depth, etc., and can be made by any suitable mass production process; however, first and last slots 90A and 90E are blocked and, in effect, terminated at a selected area along their lengths by an obstruction 93 (FIGS. 1 and 2) such as a mass of a. glass frit, for example, of the type known as Pyroceram. The slots 90A and 90E ,thus terminate nearer to left edge 70 of the plate 20 and of the panel, this being the end at which the scanning operation originates in one mode of operation of the panel.

Electrodes 110, which are used as counting or scanning anodes in one mode of operation of the panel, are seated in the slots 90B, C, and D, and these electrodes are long enough to extend beyond the left and right edges of plate 20 so that they are accessible outside the panel. Electrodes are preferably individual wires; however, they may also be plated, evaporated or otherwise formed in the slots. The electrodes 110, if separate wires, might also be secured in the slots 90 by means of a cement such as a fused glass frit or the like. An auxiliary wire electrode 120, also an anode, is seated in each of the shortened slots 90A and 90E, and these originate at the obstruction 93 and extend only beyond the left end 70 of the plate 20.

According to the invention, a cell used as an auxiliary keep-alive cell is provided in bottom plate 20 in communication with slot 150A in center plate which is described below. This auxiliary keep-alive cell includes a small hole 112 (FIGS. 1 and 3) which extends downwardly from the top surface of bottom plate 20 at about midway between the upper and lower edges of the plate 20 and in the rib 113 which lies between two slots 90, say between slots 90C and 90D. The point on bottom plate 20 at which the hole 1 12 originates lies beneath a portion of slot A in center plate 130 disposed above it. The hole 112 extends vertically downwardly to near the bottom surface where it joins a relatively large opening or chamber 114 formed in the bottom surface of plate 20. The chamber extends into the body of plate 20 and is of sufficient volume to receive a keep-alive electrode structure 115.

The keep-alive structure 1 15 comprises a radioactive material such as tritium, a radioactive isotope of hydrogen, carried on a suitable solid support, as is well known in the art. The keep-alive electrode 115 is seated in the chamber and is positioned to provide excited particles which can diffuse through hole 112 and thus into communication with slot 150A for a purpose to be described.

If desired, the chamber 114 may also include a lateral arm 118 (FIG. 4) in which the keep-alive electrode structure 115 can be seated, still in communication with hole 112 but more remote therefrom.

The chamber 114 (and 118) is hermetically sealed with a mass 119 of an amalgam of mercury, gallium, or the like. The formation of this keep-alive structure is described in detail below.

Panel also includes a center sheet or plate 130 of a dielectric material, like plate if desired, which is seated on bottom plate 20 and has a top surface 132, a bottom surface 134, an upper edge 136, a lower edge 138, a left edge 140, and a right edge 142. The sheet 130 is provided with a plurality of rows and columns of apertures or holes 144, and the bottom surface 134 thereof is provided with a plurality of generally rectangular, parallel slots 150. Slots 150 have the same width and depth and extend along sheet 130 from the lower edge 138 to the upper edge 136. The slots 150 are oriented at 90 to each of the slots 90, and thus, in effect, cross each of the slots 90 in the bottom plate 20. The array of slots 150 is suitably positioned between the left and right edges 140 and 142, respectively, of center sheet 130, with slot 150A (FIGS. 1 and 5) considered to be the first slot positioned close to the left edge 140 of sheet 130, and the last 150F being positioned close to the right edge 142 of sheet 130. The columns in which apertures or holes 144 in center sheet 130 are arrayed are generally alignedwith the slots 150C to 150F, as shown in FIG. 1, and the rows in which they are arrayed are generally aligned with slots 908, C, and D in bottom plate 20. The holes 144 are identical, and the slots 150 are identical, and each may be made by any suitable mass production process.

A plurality of electrodes, operated as cathodes, are associated with center sheet 130, and these include scanning cathode electrodes 160A, B, C, and D seated in the slots 150C, D, E, and F in sheet 130. The scanning cathode electrodes 160 are metal strips which substantially fill the slots 150 and extend along the entire length thereof and beyond the upper and lower edges of sheet 130. The cathodes 160 are oriented at 90 to the anodes 110, and each cathode crosses each anode. Each electrode 160 is provided with a plurality of tiny apertures 162 disposed along its length, with each apertures 162 being generally centrally positioned over a slot 90 (FIG. 6) in bottom plate 20 and beneath a hole 144 in center sheet 130. The cathodes 160 are identical in size and shape and can be made by any suitable mass production process.

A cathode electrode 164, used as a reset cathode, is seated in slot 150B. Cathode 164 has the same thickness and length as electrodes 160; however, it is narrower so that there are spaces 170 on either side of it which extend all along the slot 150B. Cathode 164 crosses all anodes 110 and 120.

The panel also includes a pair of cathode strip electrodes 167 and 168 (FIG. 1) used as keep-alive cathodes, and seated in slot 150A, with electrode 167 having its inner end originating at a location between slot 90D and slot 90E and extending out of the panel beyond the lower edge of the panel. Similarly, the inner end of electrode 168 originates at a location between slot 190A and slot 1908, and the electrode extends out of the panel beyond the upper edge. Electrodes 167 and 168 are identical in size and shape to electrodes 160 so that they, too, fill the slot 150A. Thus, cathodes 167 and 168 can be formed by removing a center por tion from a cathode 160.

A second group of wire electrodes 180, used as display anodes, are seated on the top surface 132 of sheet 130, or in slots (not shown) in top surface 132, each being aligned with or overlaying a row of holes 144 in center sheet 130. The electrodes 180 need not be centered over the holes; they need only communicate with the gas in the holes, with no particular alignment required.

A transparent cover or viewing plate 190 of a dielectric material such as glass completes the panel and is seated on center sheet 130. The wire electrodes 180 might be seated in slots in the bottom surface of top plate 190 (not shown), if desired. In the completed panel 10, the three plates 20, 130, and 190 are hermetically secured together by a seal 200 formed along their adjacent edges by any suitable means such as a fused glass frit (Pyroceram) or the like.

The gas used in panel 10 is introduced in any suitable manner, for example, by means of a bell jar or by means of a tubulation 203 (shown only in FIG. 2), secured to bottom plate 20 and communicating with the portion of slot E or 90A to the right of mass 93.

As described, panel 10 includes a lower layer of counting or scanning gas cells 210 (FIGS. 5 and 6) arrayed in rows and columns, with each cell comprising a portion of a lower anode electrode in slot 90, a portion of the apertured strip cathode electrode 160 above it, and the gas volume between them in slot 90. Thus, each column of counting cells is defined by each cathode 160 and its crossing of a slot 90 and the associated portion of a counting anode 110. As seen in FIG. 1, there are four columns of counting cells 210, and, for purposes of description, the first column is associated with cathode 160A, the second column with cathode 160B, the third column with cathode 160C, and the fourth column with cathode 160D. Each column of scanning cells 210 communicates with the adjacent column, that is, each scanning cell in one column communicates with the corresponding cell in the adjacent column, through the associated slot 90.

The panel 10 also includes an upper layer of display cells 220 associated with and vertically aligned with, the counting cells 210. Each display cell 220 (FIGS. 5 and 6) is made up of a portion of a cathode 160, the associated gas-filled hole or cell 144 in center sheet 130, and the associated portion of upper anode electrode 180. As with the counting cells, there are also four columns of display cells 220, each associated with a cathode 160, with the first column associated with cathode 160A, etc. v

The panel 10 also includes a column of auxiliary cells which are known variously as starter cells, reset cells, particle-supply cells, or glow-spreading cells 224 (FIG. 7), and these cells supply excited particles to facilitate the tum-on of the first column of counting cells 210 associated with cathode 160A at the beginning of a scanning cycle. For convenience, cells 224 will be called reset cells. These reset cells are arrayed in a column to the left of the first column of counting cells and communicating therewith through slots 908, C, and D. Cells 224 are constituted by the cathode strip 164 and the portion of each anode 110 and which it crosses and the gas volume in the slots 90 therebetween.

Panel also includes keep-alive cells 228 (FIG. 8) which are provided to insure firing of the reset cells 224. Keep-alive cells 228 are constituted by cathodes 167 and 168 and the anode electrodes 120 which they cross and the gas volume between them in slots 90A and 90E. The keep-alive cells 228 communicate with the reset cells through slots 90A and 90B and through the portion of slot 150A between keep-alive cathodes 167 and 168 and through the slots 90B, C, and D which slot 150A crosses. Auxiliary keep-alive cell 111 provides excited particles to the reset cells through slot 150A in plate 130 and slots 90 in plate 20. Keep-alive cells 228 are held ON continually, and keep-alive cell 1 11, by its radioactive material, provides electrons continually throughout the useful life of the material.

At this point, it might be noted that the extent to which the inner ends of the keep-alive anodes 120 can extend to the right in the panel as determined by the obstructions 93 is controlled by whether these anodes will interfere with the operation of any of the cathodes 160 and the associated counting cells. Thus, the anodes 120 and mass 93 (FIG. 2) might terminate inside the panel between reset cathode 164 and the first counting cathode 160A. If the counting cathodes are connected in groups and driven by common drivers, as described in copending application, Ser. No. 850,984 and as shown schematically in FIG. 7, with cathode 160A connected to cathode 160D, cathode 160B connected to cathode 160E, and cathode 160C connected to cathode 160F, then the anodes 120 could extend only to between cathodes 160C and 160D but not into operative relation with cathode 160D. This is because cathodes 160A and 160D are connected together and their normal operation in the scanning cycle would be disturbed.

In addition, as shown in FIG. 8, the keep-alive cathodes 167 and 168 may not extend into operative relation with the counting anodes 1 10.

In manufacturing the panel 10, all parts are prepared and assembled as described except that plate 20 has hole 112 and chamber 114 separated by a thin glass wall 300 (FIG. 10) so that the inside of the panel envelope is not exposed to the atmosphere. With the parts held together in any suitable apparatus and with the sealing material placed around the edges of the plate, the assembly is passed through an oven to fuse the sealing material, and, when the assembly is cooled, the hermetic seal 200 is formed. The panel is then pumped out through tubulation 203, baked out, filled with the desired gas through tubulation 203, and the tubulation is sealed off. Temperatures of the order of 450 C. are used in the foregoing assembly procedure.

Next, the completed panel is placed in a controlled atmosphere chamber which may be at room temperature and has an atmosphere, preferably, the same as the gas filling of the panel. The thin wall 300 is now punctured (FIGS. 3 and 4) or removed entirely to permit communication between hole 112 and chamber 114. The keep-alive electrode 115 is placed in the chamber 114, and the chamber is filled with the amalgam 119 of mercury or gallium or the like. The electrode 115 is held exposed to the hole 112 to provide electrons thereto, and the amalgam is set into chamber 114 without obstructing this relationship between electrode 115 and hole 112. The panel, with the keep-alive opening thus sealed, is held in the assembly chamber until the amalgam seal is cured and forms the desired hermetic seal, and the panel is now ready for further processing, if necessary, and for use.

Methods of making electrode 115 are well known, but it might be noted briefly that, in one suitable method, a thin film of titanium is formed on any suitable metal substrate and the tritium is sorbed into the titanium film.

Concerning the amalgam, gallium is preferred as a base material since it wets glass well. Powders of metals such as copper, gold, silver, tin, or the like, singly or alone, are added to the gallium to achieve the desired amalgam characteristics. Amalgams of this type are well known in the art, particularly the dental art, and need not be described in any greater detail here.

In the description of the operation of the invention set forth below, reference is made: to scanning or glow transfer from cell to cell or column to column. Several different types of actions occur including glow transfer from a keep-alive cell 228 to a reset cell 224, from a reset cell to a reset cell, from a reset cell 224 to a scanning or counting cell 210, from a scanning cell to a scanning cell, and from a scanning cell to a display cell 220. The exact mechanism by which each such operation occurs cannot be described with complete certainty; however, the operations may involve actual transfer of a mass of glowing ionized gas, or the diffusion of excited particles including metastable states which facilitate a new firing of an OFF cell, or both mechanisms may be involved.

In operation of the panel 10, the keep-alive cells 228 communicate with the reset cells 224 through slots A and 90E primarily, and through slot 150A and slots 908, C, and D, secondarily, and excited particles thus can difluse from keep-alive cells 228 through both paths to the reset cells 224. The most direct path for diffusion is through slots 90A and 90E to the two immediately adjacent reset cells 224A and 224E (FIG. 7) associated with slots 90A and 90E between keep-alive cathodes 167 and 168 and then through slots 90B, C, and D to reset cells 224B, C, and D. Keep-alive cell 111 provides excited particles through the aforementioned secondary path by diffusion. As noted, the keep-alive cells are always on, and, when it is desired to turn on the reset cells 224, operating potential is applied to the reset cathode 164 and to all of the anodes and 120. With the aid of the keep-alive cells, glow starts first in reset cells 224A and E and spreads immediately along the entire length of the reset cathode 164 in the spaces 170. This is the reason for having electrode 164 narrower than its slot 1503. The spread of glow along the reset cells is facilitated by the secondary diffusion path described above.

When the reset cells 224 have fired, the first column of counting cells 210 can be fired with the aid of excited particles generated in the reset cells and able to diffuse to the first column of counting cells through slots 90B, C, and D. An arrangement for using reset cells to fire counting cells is described and claimed in copending application, Ser. No. 791,208, filed Jan. 7, 1969. In addition, methods and apparatus including circuits for scanning columns of counting cells and energizing display cells therefrom are described and claimed in the above-mentioned application Ser. No. 850,984. These circuits are not shown here. In a typical scanning operation, the scanning or counting anodes 110 are connected to driver circuits for applying generally positive operating potential thereto, and each of the cathodes 160 is connected to a driver circuit for applying generally negative operating potential to each, sequentially, to cause each column of lower counting cells 120 to tire and glow. The firing of each column of counting cells, after the first has been fired, is facilitated by the diffusion of excited particles through the slots 90 from ON counting cells to the adjacent OFF counting cells to be fired. The columns of counting cells 210 are fired sequentially from left to right, as seen in FIGS. 1 and 2. This sequential firing of the columns of lower counting cells 210 is carried out cyclically from left to right. Each time the last column of counting cells at the right-hand edge of the panel is reached, the column of reset cells 224 at the left-hand edge of the panel is turned on again, with the aid of the keep-alive cells, and the above-described cycle is repeated. If desired, circuit means may be provided to sense the turn-on of the last column of counting cells 210 and automatically turn on the reset cells to start the cycle again.

When it is desired to fire cells 220 inthe upper layer to represent the display of information or the like, generally positive operating potentials are applied to the proper upper anodes 180 associated with the cells 220 to be fired and glow transfers from the associated lower cells 210 through the apertures 162 in cathode electrodes 160 to the upper cells where the glow can be viewed through top plate 190. As described above, the glow transfer is facilitated by the presence of excited particles in each of the lower counting cells 210 when it is fired.

It is clear from the foregoing description of the invention that, since there is optimum uniformity in the parts used in the display panel, optimum ease of assembly and operation can be achieved. Of course, considerable savings in parts and assembly time are also achieved.

It is clear that modifications may be made in the panels described within the scope of the invention. For example, although the panel as described is scanned from left to right, the scanning may be effected in other ways, and this might require a rearrangement of parts. In addition, although two keep-alive cells have been shown, one may be sufficient.

In general, the drawings are not intended to be dimensionally exact, and, in a typical display panel embodying the invention, the top plate 190 and bottom plate 20 are about one-fourth inch in thickness, and the center plate 130 is about 40 mils in thickness. In addition, in plate 20, slots 90 are 10 mils wide and 35 mils deep, and electrodes 110 and 120 are mils in diameter. In plate 130, slots 150 are 36 mils wide and l to 3 mils deep, with cathodes 167, 168, and 160 having approximately the same dimensions. The holes 162 in the cathodes are l to 3 mils in diameter, the holes 144 in plate 130 are 18 to 24 mils in diameter and 40 mils deep, and electrodes 180 are about 3 mils in diameter.

What is claimed is:

l. A display panel comprising an insulating gas-filled envelope including a plurality of gas-filled cells,

an anode electrode and a cathode electrode associated with each cell, and

a source of excited particles embedded in a chamber in said envelope remote from said cells and communicating from said chamber through a gas communication path with said cells, said source comprising an electrode which is adversely affected by high temperatures such as those at which said envelope is formed,

said source being sealed in said chamber by means of a sealing material which forms a hermetic seal with said envelope at about room temperature.

2. The panel defined in claim 1 wherein said sealing material is an amalgam of gallium and selected metals.

3. The panel defined in claim 1 wherein said sealing material is an amalgam of gallium and one or more metals selected from the group consisting of copper, gold, silver, and tin.

4. A display panel comprising an insulating gas-filled envelope including a dielectric bottom plate and top plate and a plurality of gas-filled cells therebetween,

an anode electrode and a cathode electrode within said envelope associated with each cell, and

an electrode source of excited particles, for facilitating firing of said cells, embedded in a chamber in said bottom plate of said envelope remote from said cells and communicating with said cells from said chamber through a hole in said bottom plate,

said source being sealed in said chamber by means of an amalgam which forms a hermetic seal with said bottom plate at a relatively low temperature below the temperatures at which said panel is assembled and processed.

5. The panel defined in claim 1 wherein said source comprises a radioactive electron-emitting electrode.

6. A display panel comprising a sandwich of dielectric plates including a bottom plate, a center plate, and a top plate,

a plurality of gas-filled glow cells disposed between said bottom plate and said center plate with an anode electrode and a cathode electrode associated with each cell, said cells being arrayed in rows and columns, and

an electrode source of excited particles disposed in operative relation with selected ones of said cells for facilitating the firing of said selected cells at a predetermined time in the operation of said panel,

said source being disposed within said bottom plate out of sight of a viewer but communicating through a gas communication path with at least one of said selected cells, said source being hermetically sealed within said bottom plate by a sealing material which forms a hermetic seal with said bottom plate at a relatively low temperature which is below the temperatures at which said panel is assembled and processed.

7. The panel defined in claim 6 wherein said sealing material is an amalgam of gallium and selected metals.

8. The panel defined in claim 6 wherein said sealing material is an amalgam of gallium and one or more metals selected from the group consisting of copper, gold, silver and tin.

9. A display panel comprising a sandwich of dielectric plates including a bottom plate, a center plate, and a top plate,

a plurality of gas-filled glow cells disposed between said bottom plate and said center plate with an anode electrode and a cathode electrode as sociated with each cell, said cells being arrayed in rows and columns,

said bottom plate having slots formed therein and comprising gas communication paths interconnecting said glow cells in a predetermined pattern, and

an electrode source of excited particles disposed in operative relation with selected ones of said cells for facilitating the firing of said selected cells at a predetermined time in the operation of said panel,

said source being disposed within said bottom plate out of sight of a viewer but communicating through a gas communication path with at least one of said selected cells, said source being hermetically sealed within said bottom plate by a sealing material which forms a hermetic seal with said bottom plate at a relatively low temperature which is below the temperatures at which said panel is assembled and processed.

10. The panel defined in claim 9 wherein said sealing material is an amalgam of gallium and selected metals.

11. The panel defined in claim 9 wherein said sealing material is an amalgam of gallium and one or more metals selected from the group consisting of copper, gold, silver, and tin.

12. A display panel comprising a sandwich of dielectric plates including a bottom plate, a center plate, and a top plate,

a plurality of gas-filled glow cells disposed between said bottom plate and said center plate with an anode electrode and a cathode electrode associated with each cell, said cells being arrayed in rows and columns, there being a first column and a last column,

a column of auxiliary cells adjacent to said first column of glow cells,

said bottom plate having slots formed therein extend- I0 ing along rows of cells an comprising gas communication paths interconnecting said column of auxiliary cells with said first column of glow cells and each column of glow cells with the adjacent column of glow cells, and an electrode source of excited particles disposed in operative relation with said column of auxiliary cells for facilitating the firing of said auxiliary cells,

said source being disposed within said bottom plate out of sight of a viewer but communicating through a hole in said bottom plate into a gas com munication path coupled to said column of auxiliary cells, said source being disposed in a chamber in said bottom plate, said chamber communicating with said hole and being hermetically sealed by an amalgam which forms a hermetic seal with said bottom plate at a relatively low temperature below the temperatures at which said panel is assembled and processed.

13. The panel defined in claim 12 wherein said hole associated with said source extends to the top surface of said bottom plate between selected ones of said slots therein and in alignment with the rib present between said selected ones of said slots.

14. The panel defined in claim 12 wherein said source comprises a radioactive electron-emitting elecf s The panel defined in claim 12 wherein said amalgam consists of gallium and selected metals.

16. The panel defined in claim 12 wherein said amalgam consists of gallium and one or more metals selected from the group consisting of copper, gold, silver, and tin.

17. The panel defined in claim 12 wherein said source comprises a radioactive electron-emitting electrode and said amalgam consists of gallium and one or more selected metal additives. 

1. A display panel comprising an insulating gas-filled envelope including a plurality of gas-filled cells, an anode electrode and a cathode electrode associated with each cell, and a source of excited particles embedded in a chamber in said envelope remote from said cells and communicating from said chamber through a gas communication path with said cells, said source comprising an electrode which is adversely affected by high temperatures such as those at which said envelope is formed, said source being sealed in said chamber by means of a sealing material which forms a hermetic seal with said envelope at about room temperature.
 2. The panel defined in claim 1 wherein said sealing material is an amalgam of gallium and selected metals.
 3. The panel defined in claim 1 wherein said sealing material is an amalgam of gallium and one or more metals selected from the group consisting of copper, gold, silver, and tin.
 4. A display panel comprising an insulating gas-filled envelope including a dielectric bottom plate and top plate and a plurality of gas-filled cells therebetween, an anode electrode and a cathode electrode within said envelope associated with each cell, and an electrode source of excited particles, for facilitating firing of said cells, embedded in a chamber in said bottom plate of said envelope remote from said cells and communicating with said cells from said chamber through a hole in said bottom plate, said source being sealed in said chamber by means of an amalgam which forms a hermetic seal with said bottom plate at a relatively low temperature below the temperatures at which said panel is assembled and processed.
 5. The panel defined in claim 1 wherein said source comprises a radioactive electron-emitting electrode.
 6. A display panel comprising a sandwich of dielectric plates including a bottom plate, a center plate, and a top plate, a plurality of gas-filled glow cells disposed between said bottom plate and said center plate with an anode electrode and a cathode electrode associated with each cell, said cells being arrayed in rows and columns, and an electrode source of excited particles disposed in operative relation with selected ones of said cells for facilitating the firing of said selected cells at a predetermined time in the operation of said panel, said source being disposed within said bottom plate out of sight of a viewer but communicating through a gas communication path with at least one of said selected cells, said source being hermetically sealed within said bottom plate by a sealing material which forms a hermetic seal with said bottom plate at a relatively low temperature which is below the temperatures at which said panel is assembled and processed.
 7. The panel defined in claim 6 wherein said sealing material is an amalgam of gallium and selected metals.
 8. The panel defined in claim 6 wherein said sealing material is an amalgam of gallium and one or more metals selected from the group consisting of copper, gold, silver and tin.
 9. A display panel comprising a sandwich of dielectric plates including a bottom plate, a center plate, and a top plate, a plurality of gas-filled glow cells disposed between said bottom plate and said center plate with an anode electrode and a cathode electrode associated with each cell, said cells being arrayed in rows and columns, said bottom plate having slots formed therein and comprising gas communication paths interconnecting said glow cells in a predetermined pattern, and an electrode source of excited particles disposed in operative relation with selected ones of said cells for facilitating the firing of said selected cells at a predetermined time in the operation of said panel, said source being disposed within said bottOm plate out of sight of a viewer but communicating through a gas communication path with at least one of said selected cells, said source being hermetically sealed within said bottom plate by a sealing material which forms a hermetic seal with said bottom plate at a relatively low temperature which is below the temperatures at which said panel is assembled and processed.
 10. The panel defined in claim 9 wherein said sealing material is an amalgam of gallium and selected metals.
 11. The panel defined in claim 9 wherein said sealing material is an amalgam of gallium and one or more metals selected from the group consisting of copper, gold, silver, and tin.
 12. A display panel comprising a sandwich of dielectric plates including a bottom plate, a center plate, and a top plate, a plurality of gas-filled glow cells disposed between said bottom plate and said center plate with an anode electrode and a cathode electrode associated with each cell, said cells being arrayed in rows and columns, there being a first column and a last column, a column of auxiliary cells adjacent to said first column of glow cells, said bottom plate having slots formed therein extending along rows of cells an comprising gas communication paths interconnecting said column of auxiliary cells with said first column of glow cells and each column of glow cells with the adjacent column of glow cells, and an electrode source of excited particles disposed in operative relation with said column of auxiliary cells for facilitating the firing of said auxiliary cells, said source being disposed within said bottom plate out of sight of a viewer but communicating through a hole in said bottom plate into a gas communication path coupled to said column of auxiliary cells, said source being disposed in a chamber in said bottom plate, said chamber communicating with said hole and being hermetically sealed by an amalgam which forms a hermetic seal with said bottom plate at a relatively low temperature below the temperatures at which said panel is assembled and processed.
 13. The panel defined in claim 12 wherein said hole associated with said source extends to the top surface of said bottom plate between selected ones of said slots therein and in alignment with the rib present between said selected ones of said slots.
 14. The panel defined in claim 12 wherein said source comprises a radioactive electron-emitting electrode.
 15. The panel defined in claim 12 wherein said amalgam consists of gallium and selected metals.
 16. The panel defined in claim 12 wherein said amalgam consists of gallium and one or more metals selected from the group consisting of copper, gold, silver, and tin.
 17. The panel defined in claim 12 wherein said source comprises a radioactive electron-emitting electrode and said amalgam consists of gallium and one or more selected metal additives. 